He’d been a birthday present for my mother. The Artful Dodger, we called him. A broken-coated Jack Russell Terrier, he sported a lopsided look, with one ear soft and dropped, the other starched upright in full salute. From the moment we brought Dodger home and posed him atop my old Paint horse, Clyde, for a quick photo-op (Dodger’s markings made him look like Clyde’s Mini-Me), it was clear that...